Accession Number : AD0692757

Title :   RELATIVISTIC COMMUNICATIONS EFFECTS ASSOCIATED WITH MOVING SPACE ANTENNAS,

Corporate Author : WASHINGTON UNIV SEATTLE DEPT OF ELECTRICAL ENGINEERING

Personal Author(s) : Holmes,James Fred ; Ishimaru,Akira

Report Date : APR 1969

Pagination or Media Count : 24

Abstract : Future space missions may require vehicles traveling at relativistic velocities. Consequently, relativistic effects will have to be considered in the development of future space communication systems. This paper presents a formulation of these relativistic communication effects which are not normally encountered by the designer. The gain function, power density available at the receiver and apparent frequency of the source can be greatly affected by the motion of the space craft antenna. In addition, the apparent direction of the spacecraft can be quite different from its actual direction for both the transmitting and receiving conditions. Formulations are presented by which these effects are described for an arbitrary antenna in terms of the antenna characteristics in its rest frame and the actual spacecraft location, a form that is convenient for the designer. In addition, numerical examples are shown to illustrate the magnitude of these relativistic effects. (Author)

Descriptors :   (*SPACE COMMUNICATIONS, RELATIVITY THEORY), (*SATELLITE ANTENNAS, GAIN), MOTION, TRANSFORMATIONS(MATHEMATICS), RADIOFREQUENCY, DOPPLER EFFECT

Subject Categories : Electrical and Electronic Equipment
      Non-radio Communications

Distribution Statement : APPROVED FOR PUBLIC RELEASE